using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using Microsoft.SqlServer.Server;

namespace BITKit.CommandPattern
{
	public interface ICommand
	{
		void Execute();
		void Undo();
	}
	public interface ICommandService
	{
		ICommand[] Commands { get; }
		event Action<ICommand> OnExecute;
		event Action<ICommand> OnClear; 
		event Action<ICommand> OnUndo;
		event Action<ICommand[]> OnRelease; 
		void Execute(ICommand command);
		void Undo();
		void Undo(int count);
		void Redo();
		void Trace(ICommand command);
		void Clear();
		void Rebuild();
		void Release();
	}

	public sealed class CommandSequence:List<ICommand>,Microsoft.SqlServer.Server.IBinarySerialize
	{
		public void Read(BinaryReader r)
		{
			Clear();
			var count = r.ReadInt32();
			for (var i = 0; i <count; i++)
			{
				Add(BITBinary.Read(r).As<ICommand>());
			}
		}

		public void Write(BinaryWriter w)
		{
			w.Write(Count);
			foreach (var x in this)
			{
				BITBinary.Write(w,x);
			}
		}
	}
}